Annotation of src/usr.bin/ssh/ssh-rsa.c, Revision 1.8.2.4
1.1 markus 1: /*
2: * Copyright (c) 2000 Markus Friedl. All rights reserved.
3: *
4: * Redistribution and use in source and binary forms, with or without
5: * modification, are permitted provided that the following conditions
6: * are met:
7: * 1. Redistributions of source code must retain the above copyright
8: * notice, this list of conditions and the following disclaimer.
9: * 2. Redistributions in binary form must reproduce the above copyright
10: * notice, this list of conditions and the following disclaimer in the
11: * documentation and/or other materials provided with the distribution.
12: *
13: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
14: * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
15: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
16: * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
17: * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
18: * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
19: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
20: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
21: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
22: * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
23: */
24:
25: #include "includes.h"
1.8.2.4 ! miod 26: RCSID("$OpenBSD: ssh-rsa.c,v 1.18 2002/04/02 20:11:38 markus Exp $");
1.5 markus 27:
28: #include <openssl/evp.h>
29: #include <openssl/err.h>
1.1 markus 30:
31: #include "xmalloc.h"
1.5 markus 32: #include "log.h"
1.1 markus 33: #include "buffer.h"
34: #include "bufaux.h"
35: #include "key.h"
1.6 itojun 36: #include "ssh-rsa.h"
1.8 markus 37: #include "compat.h"
1.8.2.4 ! miod 38: #include "ssh.h"
1.1 markus 39:
40: /* RSASSA-PKCS1-v1_5 (PKCS #1 v2.0 signature) with SHA1 */
41: int
42: ssh_rsa_sign(
43: Key *key,
1.8.2.3 miod 44: u_char **sigp, u_int *lenp,
45: u_char *data, u_int datalen)
1.1 markus 46: {
1.7 markus 47: const EVP_MD *evp_md;
1.1 markus 48: EVP_MD_CTX md;
1.8.2.3 miod 49: u_char digest[EVP_MAX_MD_SIZE], *sig, *ret;
1.2 markus 50: u_int slen, dlen, len;
1.7 markus 51: int ok, nid;
1.1 markus 52: Buffer b;
53:
54: if (key == NULL || key->type != KEY_RSA || key->rsa == NULL) {
55: error("ssh_rsa_sign: no RSA key");
56: return -1;
57: }
1.8 markus 58: nid = (datafellows & SSH_BUG_RSASIGMD5) ? NID_md5 : NID_sha1;
1.7 markus 59: if ((evp_md = EVP_get_digestbynid(nid)) == NULL) {
60: error("ssh_rsa_sign: EVP_get_digestbynid %d failed", nid);
61: return -1;
62: }
1.1 markus 63: EVP_DigestInit(&md, evp_md);
64: EVP_DigestUpdate(&md, data, datalen);
1.8.2.3 miod 65: EVP_DigestFinal(&md, digest, &dlen);
1.1 markus 66:
1.7 markus 67: slen = RSA_size(key->rsa);
68: sig = xmalloc(slen);
69:
70: ok = RSA_sign(nid, digest, dlen, sig, &len, key->rsa);
1.8.2.3 miod 71: memset(digest, 'd', sizeof(digest));
1.1 markus 72:
73: if (ok != 1) {
74: int ecode = ERR_get_error();
75: error("ssh_rsa_sign: RSA_sign failed: %s", ERR_error_string(ecode, NULL));
76: xfree(sig);
77: return -1;
78: }
79: if (len < slen) {
80: int diff = slen - len;
81: debug("slen %d > len %d", slen, len);
82: memmove(sig + diff, sig, len);
83: memset(sig, 0, diff);
84: } else if (len > slen) {
85: error("ssh_rsa_sign: slen %d slen2 %d", slen, len);
86: xfree(sig);
87: return -1;
88: }
89: /* encode signature */
90: buffer_init(&b);
91: buffer_put_cstring(&b, "ssh-rsa");
92: buffer_put_string(&b, sig, slen);
93: len = buffer_len(&b);
94: ret = xmalloc(len);
95: memcpy(ret, buffer_ptr(&b), len);
96: buffer_free(&b);
97: memset(sig, 's', slen);
98: xfree(sig);
99:
100: if (lenp != NULL)
101: *lenp = len;
102: if (sigp != NULL)
103: *sigp = ret;
104: return 0;
105: }
106:
107: int
108: ssh_rsa_verify(
109: Key *key,
1.8.2.3 miod 110: u_char *signature, u_int signaturelen,
111: u_char *data, u_int datalen)
1.1 markus 112: {
113: Buffer b;
1.7 markus 114: const EVP_MD *evp_md;
1.1 markus 115: EVP_MD_CTX md;
116: char *ktype;
1.8.2.3 miod 117: u_char digest[EVP_MAX_MD_SIZE], *sigblob;
1.2 markus 118: u_int len, dlen;
1.7 markus 119: int rlen, ret, nid;
1.1 markus 120:
121: if (key == NULL || key->type != KEY_RSA || key->rsa == NULL) {
122: error("ssh_rsa_verify: no RSA key");
1.4 markus 123: return -1;
124: }
1.8.2.4 ! miod 125: if (BN_num_bits(key->rsa->n) < SSH_RSA_MINIMUM_MODULUS_SIZE) {
1.4 markus 126: error("ssh_rsa_verify: n too small: %d bits",
127: BN_num_bits(key->rsa->n));
1.1 markus 128: return -1;
129: }
130: buffer_init(&b);
1.8.2.1 jason 131: buffer_append(&b, signature, signaturelen);
1.1 markus 132: ktype = buffer_get_string(&b, NULL);
133: if (strcmp("ssh-rsa", ktype) != 0) {
134: error("ssh_rsa_verify: cannot handle type %s", ktype);
135: buffer_free(&b);
136: xfree(ktype);
137: return -1;
138: }
139: xfree(ktype);
1.8.2.1 jason 140: sigblob = buffer_get_string(&b, &len);
1.1 markus 141: rlen = buffer_len(&b);
142: buffer_free(&b);
1.8.2.3 miod 143: if (rlen != 0) {
1.1 markus 144: error("ssh_rsa_verify: remaining bytes in signature %d", rlen);
1.8.2.2 miod 145: xfree(sigblob);
1.1 markus 146: return -1;
147: }
1.8 markus 148: nid = (datafellows & SSH_BUG_RSASIGMD5) ? NID_md5 : NID_sha1;
1.7 markus 149: if ((evp_md = EVP_get_digestbynid(nid)) == NULL) {
150: error("ssh_rsa_verify: EVP_get_digestbynid %d failed", nid);
1.8.2.2 miod 151: xfree(sigblob);
1.7 markus 152: return -1;
153: }
1.1 markus 154: EVP_DigestInit(&md, evp_md);
155: EVP_DigestUpdate(&md, data, datalen);
1.8.2.3 miod 156: EVP_DigestFinal(&md, digest, &dlen);
1.1 markus 157:
1.7 markus 158: ret = RSA_verify(nid, digest, dlen, sigblob, len, key->rsa);
1.8.2.3 miod 159: memset(digest, 'd', sizeof(digest));
1.1 markus 160: memset(sigblob, 's', len);
161: xfree(sigblob);
162: if (ret == 0) {
163: int ecode = ERR_get_error();
164: error("ssh_rsa_verify: RSA_verify failed: %s", ERR_error_string(ecode, NULL));
165: }
166: debug("ssh_rsa_verify: signature %scorrect", (ret==0) ? "in" : "");
167: return ret;
168: }
![[BACK]](/icons/back.gif){kind=icon}
Return to ssh-rsa.c CVS log ![[TXT]](/icons/text.gif){kind=icon}
![[DIR]](/icons/dir.gif){kind=icon}
Up to [local] / src / usr.bin / ssh